The present invention relates generally to a fire hydrant nozzle assembly and, more particularly, to a configuration for readily and simply attaching a bronze fire hydrant nozzle to a cast iron hydrant barrel without the use of leading caulking, screw threads, or other methods generally requiring machining. The invention also relates to avoiding un-intentional removal of the bronze nozzle as a result of the application of relatively high torque typically required to remove a protective cap.
Conventional fire hydrants comprise a vertical upstanding cast iron barrel with a plurality of discharge nozzles or outlets, attached usually at 90.degree. to the axis of the barrel. The discharge nozzles comprise separate bronze sleeve-like elements secured within annular bosses cast as a part of the hydrant barrel. Nozzles are screw threaded at an outlet end to alternately receive either a protective cap or a standard hose connection.
Typical such bronze nozzles are attached to the hydrant barrel casting by filling a large annular space between the bronze nozzle and the boss portion of the iron barrel casting with molten lead. After the lead has cooled and solidified, it is then caulked (pounded with a special chisel-like tool) to compact it and effect a seal. In order to help prevent nozzle rotation or blow out, some designs additionally incorporate a stop, cast in the bronze, which mates with a slot in the hydrant boss, or vice versa.
Replacement of a damaged nozzle involves a fairly complicated procedure. Initial removal requires remelting the lead, and re-installation of the nozzle or a replacement nozzle requires pouring molten lead into a vertical annular space since the hydrant barrel will typically be standing vertically in the field. Replacement also requires caulking, a procedure requiring considerable skill and craftsmanship.
Another type of prior art design employs machined screw threads on the bronze nozzle for attachment to the hydrant boss, and a small gasket such as a rubber O-ring to provide a seal. This design approach also requires that mating threads be provided on the inside of the hydrant boss, such as by machining. The disclosure of the Dunton U.S. Pat. No. 3,534,941 provides a typical example of such a fire hydrant including machined screw threads on the bronze nozzle.
To prevent turn out of a machined screw thread type nozzle when the protective cap is removed, two general approaches have previously been employed. One approach, such as disclosed in the Dunton U.S. Pat. No. 3,534,941, is to provide a small pin or screw fitted in aligned apertures extending radially through portions of the nozzle and hydrant barrel. Another approach is to use left-hand threads for the connection of the nozzle to the hydrant barrel. These left-hand threads are tightened as torque is applied to remove the nozzle cap, which has standard right-hand threads. With either of these two approaches, adhesives are sometimes applied to the threads to provide additional resistance to turn out.
Removal of a machined and threaded-nozzle typically requires removal of the pin by drilling, unscrewing or driving inwardly, and then the application of a large amount of torque to break the adhesive or the corrosion products built up in the iron-to-bronze threaded connection.
One drawback to the threaded in nozzle designs is that alignment of the apertures for the pin is dependent upon the location of the start of the first threads on the circumferences of the nozzle and boss, as well as the precise degree of tightening required. Tapping and thread cutting operations are normally independent of angular orientation with respect to circumference, and dependent only upon position with respect to the axis of a cylinder. Therefore, alignment of predrilled holes in the hydrant nozzle using threads to attach it to the boss is almost impossible. Consequently, the holes for the pin in such designs must be drilled after screwing the nozzle into the hydrant boss, making field replacement a difficult task since the new nozzle must be drilled to accept the pin in the field.
Another disadvantage of some designs of the type employing machined threads in the hydrant boss and nozzle is that a wrench-engaging lug is required to be cast on the inside of the bronze nozzle, the lug extending into the waterway. This lug is used to allow a wrench, placed in the nozzle, to engage the nozzle for tightening into the hydrant boss. However, such lugs inhibit the flow of water and increase pressure loss through the hydrant.
The present invention provides a nozzle assembly wherein the nozzle is attached to the barrel of a fire hydrant without the use of lead caulking, screw threads, or other methods generally requiring machining. Additionally, the problem of the bronze nozzle unintentionly being removed as a result of the high torque necessary to remove a nozzle cap is effectively dealt with.